Heretofore it has been suggested, in an effort to produce more oil from a given subsurface geologic formation, to employ an enhanced oil recovery process which utilizes a gas under pressure. The gas is chosen for its ability to become miscible with the oil in the formation at the temperature and pressure conditions prevalent in the formation itself thereby developing, in-situ in the formation, a transition zone composed of light hydrocarbons from the oil and the injected, pressurized gas. This zone or phase is quite mobile and pushes its way through the formation forcing more oil out of the formation and into a producing well which the transition zone is moving toward.
In general, large quantities of gas are employed in such processes because pressures in the thousands of psig are normally employed. Often incremental oil recovery due to the enhanced oil recovery process is not as great as is desired because of a phenomenon known in the art as "fingering". When the injected gas and/or transition zone preferentially follow certain narrow paths through the formation rather than uniformly spreading out throughout the formation they are said to be fingering. The fingering process bypasses substantial amounts of oil in the formation which would otherwise be mobilized for recovery, and, therefore, is undesirable.